rlshrtnr.rb

rlshrtnr.rb

# shorten a URL
# curl -X POST --data "url=http://livingsocial.com" localhost:9292
#
# -->  returns the shortened url in the body
#
# to retrieve a shortened URL
# open http://localhost:9292/a723bae
#

require 'rubygems'
require 'rack'
require 'zlib'

HTTP_HOST = "http://localhost:9292"

class Shortener

  def initialize
    @url_store = {}
  end

  def store_url(url)
    key = Zlib.adler32(url).to_s(26)
    @url_store[key] = url
    "#{HTTP_HOST}/#{key}"
  end

  def get_url(key)
    @url_store[key.gsub(/^\//,"")]
  end

  def call(env)
    case env['REQUEST_METHOD']
    when "GET"
      url = get_url env['REQUEST_URI']
      if url
        [302, {"Location" => url}, ""]
      else
        [404, {}, "Hello Rack!"]
      end
    when "POST"
      post_data = env["rack.input"].readline
      _, url = post_data.split(/=/)
      shortened = store_url(url)
      [201, {}, shortened]
    else 
      [500, {}, "Not implemented !"]
    end
  end
end

Rack::Handler::Mongrel.run Shortener.new, :Port => 9292